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This thesis investigated the use of synthetic aperture techniques to achieve a long effective aperture, high resolution, imaging sonar. The approach included a full simulation of the system using the MATLAB programming environment that provided a model for developing six data processing algorithms and a working 25KHz, 1 m baseline, air medium synthetic aperture sonar. The six azimuthal processing techniques included: (1) a normal, real aperture, (2) an unfocussed synthetic aperture, (3) a hybrid focussed-unfocussed system, (4) a fully focussed one line algorithm, (5) a limited two-dimensional, fully focussed algorithm and, (6) a limited two-dimensional, hybrid focussed-unfocussed algorithm. This thesis compared the run times, resolutions and signal to noise ratios achieved by the six techniques both in simulation and experimental measurements collected with the actual prototype.

Aperture averaging effects on the measurement of scintillation and on the temporal-frequency power spectrum have been examined in the marine boundary surface layer using a He-Ne (6328 A) laser beam propagating over ...

In order to improve the prompt response from an impulse radiating antenna (IRA)number of studies have suggested controlling the spatial distribution of the aperture fields by changing the feed arm angle. Other work has ...

A computer model for axially symmetric dielectric radomes in the near field of a circular aperture has been developed. This model, based on a method of moments solution for bodies of revolution. is used to determine the ...